Sound-box.



E. H. -KAUFMAN.

SOUND BOX.

APPLICATION FILED AUG.27. 1314.

1,1 5 1,472. Patented Aug. 24, 1915.

A TTOH/VEV EUGENE H. KAUFMAN, OF NEW YORK, N. Y., ASSIGNOR 0E. ONE-HALF T0 HARRISON w. ROGERS AND CHARLES w. EBE-LING, BOTH OF NEW YORK, N. Y.

SOUND-BOX.

mamas.

Specification of Letters Patent.

Patented Aug. 2a, 1915.

Application filed August 27, 1914. A Serial N 0. 858,819.

To (177 0710121 it may concern Be it known that I, EUGENE H. KAUFMA a citizen of the United States, and a resident of the city of New York, borough of Manhattan, in the county and State of- New York, have invented a new and Improved Sound-Box, of which the following is a full, clear, and exact description.

My invention relates to sound reproducing and recording instruments, and has reference more particularly to a sound box having a stylus bar, a diaphragm, and means for supplying an air current to the sound waves produced by the diaphragm whereby the sound waves produced at the diaphragm by the stylusbar are intensified.

The invention is' also characterized by the provision of an exceedingly elastic medium between the stylus bar and the diaphragm.

Further, the sound box is characterized by having its diaphragm secured betweenthe center and the periphery thereof. It is still further characterized by an air supply adapted tocreate a current from, the side of the diaphragm not facing the stylus bar.

The object of the invention is to provide a strong, simple, inexpensive, and efficient sound box which is particularly adapted for use in large halls, theaters, hotels, etc., and the tone of which is not distorted although greatly magnified. 1

1V ith the above and other objects in view, the nature of which will more fully appear as the description proceeds, the invention consists in the novel construction; combination and arrangement of parts as herein fully described, illustrated and claimed.

In the accompanying drawings, forming part of the application, similar characters of reference indicate corresponding parts in all the views, and Figure 1 is a front elevation of the sound box; Fig. 2 is a side elevation thereof; Fig. 3 is a vertical, axial section on line 33, Fig. 1 or 33, Fig. 5; Fig. 4 is a similar section on line 41, Fig. 5; Fig. 5 is a cross section on line 55, Fig. 3; and Fig. 6 is a cross section on line 6'6, Fig. 4. 4

Referring to the drawings, 7'is an air drum having an eccentric inlet 8 at the rear end thereof and a central outlet 9 in the front thereof. Concentric with the drumis a tube 10, one end of which projects through the rear end of the drum, where the tubular member is rigidly secured thereto in any through the outlet.

suitable way and so that no air can pass between the rear end of the drum and the tubular member. The other end of the tube 10 is provided with an end wall 11, the outer surface of which is-in alinement with the outer surface of the front end of the drum 7. The diameter of the air outlet is preferably greater than the exterior diameter of the tube 10; and the end of the tube within said air outlet is preferably enlarged to form a head 12, which is spaced by a small annular gap 13 from the wall of the air outlet 9.

The end wall 11 is provided with a series of end slits or notches 14 which facilitate the passage of the air from the drum It will be noted that these slits or notches do not pass to the interior of the tube 10 (see Fig. 4). The end wall 11 is also provided with a series of slits 15 not extending to the periphery, although extending farther toward the center of the tube than the end slits 14. The said slits 15 establish communication between the outerface of the end wall and the interior of the tube, while the slits l4 establish communication between the interior of the drum and the outer face of the end wall 11. It will be notedthat allthese slits are radial and that the shts 14 and 15 are in successive alternation. The end wall 11 is also provided with a central aperture 16 leading from the outer surface to the interior of the tube 10.

An annular member 17 is secured to the front end of the drum 7 by screws 18, or any other suitable means. The central bore 19 .of the annular member is preferablylarger thanthe central bore of the drum forming the outlet 9, so that an annular surface 20 is formed on the front end of thedru'm, which forms an additional surface for a diaphragm 21 which rests against the outer surface of the end wall 11. The bore 19 is enlarged toward its outer end and threaded to receive .a plug or cap 22, the end 23 of which fits snugly into the bore 19of the annular member 17 The plug 22 is provided with a central bore 24, and the face-of theend 23 of the plug has an annular raised portion 25 adapted to clamp the diaphragm between the outer surface of the endwall 11 and the plug 22. The diaphragm I prefer to use is made of paper but it is understood that any other suitable material may be used; and it will be noted that by clamping the diaphragm as stated the same has two annular vibrating regions, one at the center thereof and the other peripheral or marginal. The end 23 of the plug is provided with slits 26 and 27, preferably radiating from the center. The slits 26 have their bottoms perpendicular to the axis of the bore 24:, while the slits 27 have their bottoms inclined to the axis of the plug, the depth of the slit increasing from the periphery toward the center, as best seen in Figs. 3 and 4. It will be noted from Fig. 5 that the slits 26 and 27 alternate. These slits establish communication between the bore 24 and the peripheral vibratory portion 'of the diaphragm, and also establish radial vibratory portions in the diaphragm by the portions of the slit cutting through the annular raised portion 25. That is to say, the diaphragm clamped by the cap or plug 22 has spaced non-vibratory portions intermediate the periphery and the center thereof, or the diaphragm has a central and peripheral vibrating portion united by radial vibrating portions. The bore 24: at the opposite end is enlarged, as shown in dotted line in Fig. 1, and thereat a valve 28 is provided. The valve 28 is guided in its movement by pins 29 carried by the cap 22. valve has a stem 30 the extremity of which contacts with a stylus bar 31 secured to the plug 22 by members 32, which members have their ends jammed in the cap and the stylus bar and form supports for the stylus bar. The lower end of the stylus bar has a socket provided with a clamping member 33 whereby a needle 3% can be secured to the stylus bar. The upper end of the stylus bar 31 is bifurcated, as shown at 35, and therebetween a neck 36 of a cap 37 is engaged. The neck 36 carries a pair of rubber washers 38, one at each side of the stylus bar, whereby a resilient connection between the cap 37 and the stylus bar is formed. The cap 37 engages a threaded stud 39 carried by the plug 22. By moving the cap 37 on the stud 39 the pressure of the stylus bar on the valve 28 may be varied, and also thereby the displacement of the valve is varied. It will be noted. that the valve 28 at one end of the bore 2& and the diaphragm at the other end thereof form an air column between the diaphragm and the stylusbar. Y

The vibration of the stylus bar received from the needle 34: moving on the disk 40 is transmitted to the valve' 28, which sets the column of air in the bore 24 andthe slits 26 and 27 into vibration. This vibration is transmitted to the diaphragm, as stated above, which is free to vibrate in the central and the peripheral parts thereof and also in parts connecting the central to the peripheral part of the diaphragm. This vibration of the diaphragm is transmitted to the air I column in the tube 10. The, current of air supplied to the drum 7 through the inlet 8 is preferably of about four to six pounds The pressure, and its main eifect is on the peripheral part of the diaphragm through the slits 14 before it enters into the tube 10 through the slits 15 (see Fig. 4). This constant pressure of the air on the peripheral part of the diaphragm causes the air present in the bore 21 and the slits thereof to maintain the valve 28 in contact with the stylus bar 31; and the vibration of the stylus bar 31' controls the communication between the aircolumn in the bore 21 and the atmosphere, and also sets the said column of air in the bore 21 into vibration, as above stated. It will be noted that the air from the drum 7 enters the tube 10 adjacent the periphery thereof, creating 'a current of air at the face of the diaphragm 21, not directly affected. by the stylus bar. This air current causes the intensification of the sound waves produced in the tube 10 by the diaphragm under the influence of the stylus bar. 3

From the foregoing description, taken in I connection with the accompanyingdrawings, the advantage of the construction and operation of the device shownwill be readily understood by those skilled in the art to which the invention pertains; and while I have described the principle of operation, together with the device which I now consider to be the best embodiment thereof, I desire to have it understood that the device shown is merely illustrative and that such changes may be made when desired as are within the scope of the appended claims.

Having thus. described my invention, I claim as new and desire to secure by Letters Patent:

1. In a sound box, a drum having an air inlet and an air'outlet, a diaphragm at the outlet, means for securing the diaphragm at the outlet, whereby the peripheral part of the diaphragm is free to move to and from the air outlet of the drum, and a tubular member associated with said securing means and adapted to receive and direct the air coming .from the drum outlet to the diaphragm.

2. In a sound box, a'drum having an air 1 outlet of the drum to the interior of the tube.

3. In a sound box, a drum having an air inlet and an air outlet, a diaphragm controlling the air outlet with one face, a plug engaging the diaphragm at the opposite face, said plug having a central bore and an annular raised portion at the end engaging the plug is in communication with'the peripheral faceof thediaphragm.

4. In a sound box, a tubular member having a centrally apertured end wall, said end wall having a series of radial end slits extending from the-lateral surface of the tube to the outer surface of the end wall and a series of radial slits from the outer surface .to. the inner surface of the end wall, means for supplying an air current about the outer lateral surfaceiof the tubular member adj acent the end wall, a diaphragm engaging the outer surface of the end wall and controlling the current ofair, a centrally apertured plug clamping said diaphragm to the end wall, said plug having an annular raised portion whereby the diaphragm is clamped to the end wall between the center and periphery thereof, the end of the plug engaging the diaphragm having a series of radial slits establishing communication between the peripheral part of' the diaphragm and the cen-. tral bore of the plug, a valve'controlling the communicationof the bore with the atmosphere, and a stylus bar for influencing the movement of the valve.

5. In a sound box, a drum having an air inlet, a tubeassociated therewith and forming with the drum an annular air outlet therefrom, said tube having an apertured end wall at the annular air outlet, a dia-- phragm, and meansfor securing the dia phragm to the end wall in regions between the central and peripheral parts thereof, the

peripheral face part of the diaphragm controlling the annular air outlet.

6. In a sound box',-a drum having an air inlet, a tube associated therewith and formingwith the drum an annular air outlet therefrom, said tube having an end wall at the annular air outlet, a diaphragm, and means for securing the diaphragm to the end wall in regions between the central and peripheral parts thereof, the peripheral face of the' diaphragm controlling the annular air outlet, said end wall having a series of 1 slits directed from the lateral surface of the tube to the outer surface of the end wall and 'adapt edto establish communication between the annular outlet and the peripheral face of the diaphragm, said end wall having also a series of slits connecting the outer surface of the end wall with the inner surface thereof, said second slits being adapted to direct the air from the diaphragm to the interior of the tube.

7. Ina sound box, a diaphragm and means engaging the diaphragm so that the centrali and peripheral parts of the diaphragm are} free to vibrate.. t

8. In a sound box, a diaphragm, and; means engaging the diaphragm so that the central and peripheral parts of the d-iaphragm are free to vibrate, said diaphragm having at one face thereof radialportions which are not engaged by the means engag- EUGENE H. KAUFMAN Witnesses: I

ALEX. YoKnL, .HARRY RULIN. 

